Toxins from a number of species of Conus (magus, striatus, obscurus, tulipa, purpurascens, radiatus, californicus, textile geographus and pacificus) identified and partially purified in the different projects will be purified to homogeneity using a variety of chromatographic techniques and their structure determined using a combination of Edman degradation and mass spectrometry of the intact and enzymatically or chemically hydrolyzed peptides. In particular, mass spectrometry of novel conotoxin peptides will be used to determine post translational modifications including acylation, glycosylation, phosphorylation, sulfation and amidation. Native structures will be duplicated by total synthesis using the solid phase approach and specific analogs will be designed to generate appropriate tools for the characterization of the particular toxin's functions. Sequence and structure analysis of the synthetic peptides will also be carried out using Edman degradation, amino acid analysis and mass spectrometry. The physicochemical properties of native and synthetic replicates will be compared as a proof of structure. Disulfide bridging arrangement of the novel cyclic synthetic peptides (shown to be identical to the native peptides) will be determined using a combination of HPLC, Edman degradation, mass spectrometry, enzymatic and chemical hydrolysis and partial reduction techniques. Appropriate support and solvent systems will be tested to increase the chromatographic resolution and sensitivity of LC/MS for the analysis of native conotoxin peptides. The analytical tools and procedures which we make available include a variety of chromatographic procedures, capillary zone electrophoresis, synthesis, enzymatic or chemical hydrolysis strategies, mass spectrometry and Edman sequencing. This core, by bringing together the expertise and instrumentation necessary to apply all these tools and procedures, will enable members of this program project to reach their respective goals.